Serum albumin is the major protein component of serum in higher species. Its role is in maintaining osmotic balance and it is involved in the binding and transport of sparingly soluble metabolic products from one tissue to another, especially in the transport of free fatty acids. Human serum albumin is used in therapy for the treatment of hypovolemia, shock and hypoalbuminemia. It is also used as an additive in perfusion liquid for extracorporeal circulation. Furthermore, human serum albumin is frequently used as experimental antigen.
Human serum albumin is composed of a single long polypeptide chain comprising nearly 600 amino acid residues. The amino acid sequence thereof is published. (See e.g. Lawn R. M., et. al., Nucleic Acids Research, Vol. 9, No. 22 (1981) pp. 6103-6113)!. Commercial human serum albumin is prepared from human plasma. The availability of human plasma is limited.
Careful heat treatment of the product prepared from human plasma must be effected to avoid potential contamination of the product by hepatitis B virus and HIV virus.
Since one of the characteristics of HIV virus is to frequently change its antigenic structure, there are no guarantees that it will not develop heat resistant variants.
Obviously, there is a need for artificial authentic human serum albumin that can be produced in unlimited quantities.